ersc 1p92extreme earth final exam: wednesday, december 3, 2008 1400h – 1600h wcibds - ian d....
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ERSC 1P92 Extreme Earth
Final Exam:
Wednesday, December 3, 2008
1400h – 1600h
WCIBDS - Ian D. Beddis Gym
110 multiple choice or “figure” questions to be answered on SCANTRON sheets
Questions will be based on material covered over the entire course.
The nature of scientific ideasSpeculation
HypothesisTheory
Law
Geology 001: the basics
Igneous RockSedimentary Rock
Metamorphic Rock
Fossils
The geologic cycle
A Brief History of GeologyHerodotos Aristotle Theophrastus St. Thomas Aquinas
Leonardo da Vinci James Ussher
Neptunism versus Plutonism
Abraham Werner
James Hutton and the Principle of Uniformitarianism
Georges Cuvier Charles Lyle
Catastrophism in the 20th Century
The Origin of the Solar System
Nebular Hypothesis
The Planets of the Solar System
The early history of the Earth
How did the Moon form?
Comets, Asteroids and Meteoroids
Asteroids (rocky bodies)
Meteoroid
Meteor
Meteorite
Bolide
Comets: dust and ice.
The Risk of Space Objects to Humans
K/T boundary impact
Tunguska Event
Comet SL-9 impact on Jupiter
What happens when a meteoroid or asteroid reaches the Earth?
Heat wavePressure wave
Impact crater formation
What is the frequency of impacts with Earth?
Near Earth Objects
Evaluating the risk of asteroid impacts.
Impact craters on Earth
How they form.Crater anatomy.
Major craters on Earth.
Plate Tectonics defined.
What did Plate Tectonics replace?
Alfred Wegener and Continental Drift.
Evidence
Theory
Outcome
Contracting Earth Theory
Geomagnetism
Earth’s Magnetic Field
Geodynamo
magnetic declination
secular variation
Orientation of the Earth’s magnetic field.
Magnetization of rocks
Remnant magnetic signature (RMS)
Magnetic Anomalies
Apparent Polar Wandering
Apparent polar wandering paths pointed to continental drift.
Sea Floor Stripes and Sea floor Spreading
Polar reversals
Plate TectonicsStructure of the Earth
USGS
Plate Boundaries
Transform Margins – Horizontal slip
Oceanic Trench– Convergence
Oceanic Ridge– Divergence
But what drives plate tectonics?
Anatomy of an Earthquake
Earthquakes
What is an Earthquake?
Shockwaves generated by energy released as adjacent rock bodies suddenly move.
Types of Shockwaves
L-waves (surface waves)
S-waves(secondary or shear waves)
P-waves (primary waves)
Intensity
Magnitude
Damage due to earthquakes
Surface vibration
Landslides
Liquefaction
Tsunamis
Distribution of Earthquakes
1. Along oceanic trenches.
2. In regions of continental collision.
4. Within plates, well away from plate margins.
3. Along oceanic ridges and transform faults.
Predicting earthquakes
Long term prediction
Recurrence rates
Seismic Gaps
Short term prediction precursor events
Seismic wave velocities Ground level deformation
Groundwater Chemistry Microearthquake swarms
Direct Sensors Animal warnings
The Great Canadian Earthquake???(Evidence for a southern BC megaquake)
Early evolution of the Earth and its atmosphere.
Formation of the Earth’s core and crust.
The Earth’s atmosphere and the evolution of early life.
Climate versus Weather
Weather: the condition of the atmosphere at a particular point in space and time.
Climate: the average weather for a defined region.
Climatic Radiative Balance and Radiative Forcing
Climate Change Over Geologic Time
Climatic fluctuation over the Tertiary and Quaternary periods.
Conditions in the Cretaceous
Much warmer as CO2 levels were elevated due to an increase in volcanic activity.
4 glacial periods
Global warming and glaciers
Mild winters, abundant snow and cool summers.
Cold, dry winters, hot summers.
Glaciers will not develop.
Glaciers develop.
Milankovich Cycles
Carboniferous/Permian
Cooling due to CO2 removal by extensive weathering.
Snowball Earth
That 600-700 million years ago the Earth was effectively covered by glacial ice, including 500 to 1500 m thick sea ice cover.
Volcano: A mound of material that is extruded to the Earth’s surface from a vent that is connected to a magma chamber via a feeder conduit.
SiO2 content controls viscosity of the magma which in turn controls the amount of gas in the magma and its explosivity.
Types of volcanic deposits
Lava: very fluid, low viscosity magma at the Earth’s surface.
Pahoehoe
Aa
Pillows
Tephra: Ash, lapilli, blocks and bombs.
Pyroclastic material
Tuff
Ash fall
Lahar
Nuée Ardente
Shield volcanoes:
dominated by lava flows.
Cinder cones:
Isolated cones dominated by
pyroclastics.
Stratovolcanoes:
mixture of lavas and
pyroclastics.
Prediction of Volcanic Eruptions
Short-term prediction
Surface tilting: recognition of changes in the land surface due to building pressure in the conduit.
Gas emissions: rates of emission and type of gas changes in some volcanoes.
Earthquakes: generated as the magma moves up the feeder conduit to the vent.
Identify the distribution, frequency, style of eruption, etc.
Determine local risks to specific hazards.
Long-term prediction
The impact of volcanic eruptions
Global Climate Change
Volcanic Explosivity Index
Mt. Pelée (1902)
Major Historic Eruptions
Tambora (1815)
Krakatoa (1883)
Krakatoa (535 AD)?
Super Volcanoes (>1,000 km3 of ejecta)
Toba
Yellowstone
Volcanoes in Space